General anesthesia relies on a combination of drugs to achieve hypnosis, analgesia, and immobility during surgery. Key agents such as propofol, sevoflurane, fentanyl, and neuromuscular blockers act through distinct mechanisms, including GABA-A receptor modulation and inhibition of pain pathways via μ-opioid receptors. Muscle relaxants further contribute by interfering with acetylcholine at the neuromuscular junction. The pharmacokinetics of these drugs determine their onset, duration, and recovery profile, while pharmacodynamics influence their clinical effects and potential adverse reactions. Patient-specific factors, such as age, obesity, and comorbidities, play a crucial role in drug selection and dosing. A thorough understanding of these pharmacological principles is essential for safe and effective perioperative management.